The invention relates to a suction disc mounting arrangement for supporting articles on smooth surfaces, including a housing with an interior space which is delimited by a plate-like suction cup. The suction cup is provided with an operating element by which the suction cup can be pulled into the interior space of the housing for generating a vacuum between the suction cup and a smooth surface on which the suction cup is disposed for firmly holding the housing on the smooth surface.
Such suction disc mounting arrangements are known in the art and used for many applications for mounting articles to smooth surfaces. However, the surface must be planar and be free of dirt or dust.
It is an important advantage of such suction disc mounting arrangements, that the structures can be removed again from the smooth surface without traces so that articles can be mounted to smooth surfaces which must not be damaged.
Since the suction cup is pulled into the housing cavity, a hollow space is formed between the suction cup and the smooth surface on which it is disposed so that a vacuum is generated between the suction cup and the smooth surface by which the suction cup and, together therewith the housing is firmly attached to the smooth surface.
The vacuum generated between the suction cup and the smooth surface is greater the tighter the suction cup is dispose on the smooth surface before it is pulled into the housing of the suction disc mounting arrangement. The operating structure for the suction disc is therefore so designed that, in a rest position, the suction disc is disposed directly adjacent, that is in contact with, the smooth surface or is even pressed onto the smooth surface to which it is to be attached. However, because of manufacturing tolerances, the suction disc may not always be so arranged that it is disposed directly adjacent the smooth surface or flatly engages the smooth surface.
It is the object of the present invention to provide a suction disc mounting arrangement, which has a high suction force for supporting an article on a smooth surface and which reliably engages the smooth surface with a high vacuum force.
In a suction disc mounting arrangement for supporting objects on smooth surfaces wherein a suction disc is supported in a housing cavity in which also an operating element is movably disposed and connected to the suction disc and operating means are supported on the operating element for pulling the suction disc into the housing cavity, a compression spring element is disposed in the housing behind the operating element in a housing sleeve so as to bias the operating element and together therewith the suction disc outwardly from the housing and into contact with a smooth surface when the disc mounting arrangement is disposed on such smooth surface for creating a relatively high vacuum, when, upon actuation of the operating element, the suction disc is pulled into the housing cavity.
Since the spring providing for engagement of the suction disc with the smooth wall is disposed between the operating element and the housing cavity end wall, the suction cup can be pulled fully into the housing cavity whereby the displacement space for the suction discs is increased without an increase of the housing cavity. It is noted that there is always some air left between the suction disc and the smooth wall so that no absolute vacuum can be generated. But the greater the vacuum generated, the greater is the retaining force with which the housing is fixed to the smooth surface. And with the arrangement according to the invention, a relatively high vacuum can be generated with a relatively non-protrusive housing.
The spring element engages the operating element in the sleeve of the housing and presses the suction disc into firm engagement with the smooth surface when the housing is placed onto the smooth surface independently of the manufacturing tolerances. It is therefore made sure that the suction element is always in appropriate contact with the surface to which the housing is to be attached for generating optimal suction forces.
It is particularly advantageous if the spring element disposed in the housing sleeve is a coil spring since such a spring can easily be accommodated in the housing sleeve. There is sufficient space in the housing sleeve that the spring can be as strong as desirable. If the spring would not be accommodated in the housing sleeve the space for the spring element which then would have to be in the housing recess, would be very limited, and also the suctioning stroke of the suction element would be limited thereby. As a result, the holding force generated by the suction disc would be correspondingly smaller. With the spring element disposed in the housing sleeve as a coil spring which, permits the use of a relatively long spring, a spring with a relatively high force can be selected as the spring force may not increase excessively when compressed to the desired degree. With the relatively large spring force, the suction element is also tightly engaged with the smooth support surface, whereby, as explained earlier, a large suction force can be generated and relatively heavy articles can be supported by the suction disc mounting arrangement.
It is quite advantageous if the operating element in the housing sleeve is provided in the form of a rod on which the coil spring element is seated. Preferably, a compensation element is disposed between the coil spring and the rod to improve the force transfer from the coil spring to the operating element and the suction element. The compensation element also facilitates the mounting of the coil spring on the operating element, which is particularly advantageous upon assembly of the suction disc mounting arrangement.
In an embodiment of the invention a lifting arm provided with cam structures at opposite sides thereof is pivotally supported on the operating element for lifting the operating element and the suction element. Since, for the lifting of the operating element, an operating arm with cam structures at opposite sides of the operating element is used, the force for lifting is distributed to two levers and the lifting force is evenly distributed, the operating arm and the cam structures may be of a relatively lightweight design for accommodating the required forces. Furthermore, the lifting force on the operating element is centered so that no torque or side force acts on the operating element and canting or cogging of the operating element in its tubular guide bore is prevented. Also, the operating mechanism is highly reliable and the suction force is increased since the suction element is pulled evenly off the smooth support surface.
In a particular embodiment, a support arm is attached to the housing sleeve of the suction disc mounting arrangement which support arm comprises a flexible tube with rod disposed in the flexible tube and consisting of a material which permits bending of the support arm maintains the shape of the support arm to which it is bent. At its axial end, the rod is provided with plug-like end members on which the flexible tube is firmly supported so that the rod and the flexible sleeve form a compact unit mounted with one end on the suction disc mounting arrangement and carrying at its free end means for supporting objects. The flexible tube preferably is a corrugated plastic tube and the rod disposed in the corrugated plastic tube is preferably an aluminum rod.
The means for supporting objects preferably comprises a support plate provided with a sleeve portion, which is firmly connected to the free end of the support arm by way of the plug disposed at the end of the flexible tube and the rod. The support plate includes means for engaging various objects supported thereon.
Preferably, the engaging means are angled hook-like holding members as disclosed in applicants U.S. Pat. No. 5,740,995. Objects can then be supported on the support plate in selectable orientations. By means of the holding members objects with corresponding openings can be rapidly and reliably connected to the support plate and can be removed just as rapidly and easily.
If the object to be supported on the support plate does not have the necessary openings an adapter plate may be used which at one side has the openings for engagement with the support plate and at the opposite side is provided with elements suitable for engaging the particular object. The adapter plate may be provided for example at the opposite side with a self-adhesive surface or a hook and loop structure.
Further features and advantages of the invention will be described below on the basis of the accompanying drawings.